1. Field of the Invention
The present invention relates to an accelerator opening degree sensor which constitutes an electronic control throttle system carried on an automobile or the like, for detecting a pedaling amount of an accelerator pedal.
2. Description of the Related Art
The electronic control throttle system, which is carried on an automobile or the like, is hitherto provided with a sensor for detecting the amount of pedaling of an accelerator pedal (pedaling amount) by a driver. The sensor is constructed such that an output voltage corresponding to the pedaling amount is obtained. The sensor is connected to the accelerator pedal via a wire or a link (see, for example, Japanese Patent Publication No. 63-34307).
In the case of the accelerator pedal described above, the sensor and the accelerator pedal are constructed separately. The sensor and the accelerator pedal are connected with each other via the wire or the link. For this reason, it has been difficult to realize a light weight and a low price of the sensor and the accelerator pedal.
In the case of the accelerator pedal described above, a little dispersion sometimes arises in the stroke range of the accelerator pedal. As a result, for example, when the accelerator pedal is maximally pedaled, the output voltage from the sensor exceeds a predetermined limit value (disorder judgement value) in some cases. In such a case, there is a possibility to make erroneous detection that any disorder occurs in the sensor.
In order to avoid the problem as described above, a method is conceived to decrease the dispersion of the stroke range of the accelerator pedal. However, for this purpose, it is necessary to use a stopper which has high positional accuracy and which is capable of enduring the pedaling force exerted on the accelerator pedal by the driver. Therefore, it is feared that the cost is greatly increased.
Another method is also conceived, in which any stopper is provided for the sensor. However, in the case of such an accelerator pedal in which the sensor and the accelerator pedal are connected via the wire as described above, the structure becomes more complicated. In such an arrangement, it becomes more difficult to realize a light weight and a low price of the sensor and the accelerator pedal.
Still another method is also conceived, in which the ratio of change (slope) of the output voltage is decreased with respect to the pedaling amount of the accelerator pedal. However, in this case, it is feared that sufficient output voltage is not obtained within the stroke range.
The present invention has been made in order to overcome the inconvenience as described above, an object of which is to provide an accelerator opening degree sensor which makes it possible to realize a light weight and a low price and which makes it possible to obtain a sufficient and effective output voltage within a stroke range of an accelerator pedal.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which a preferred embodiment of the present invention is shown by way of illustrative example.